Mortgages and Notes Payable (Narratives) (Details) (USD $)	3 Months Ended		9 Months Ended			0 Months Ended	9 Months Ended		0 Months Ended	9 Months Ended		0 Months Ended	9 Months Ended						0 Months Ended
	Aug. 31, 2012	Feb. 29, 2012	Aug. 31, 2012	Aug. 31, 2011	Nov. 30, 2011	Jul. 31, 2012 Senior Notes due 2014 at 5 3/4%	Aug. 31, 2012 Senior Notes due 2014 at 5 3/4%	Nov. 30, 2011 Senior Notes due 2014 at 5 3/4%	Jul. 31, 2012 Senior Notes due 2015 at 5 7/8%	Aug. 31, 2012 Senior Notes due 2015 at 5 7/8%	Nov. 30, 2011 Senior Notes due 2015 at 5 7/8%	Jul. 31, 2012 Senior Notes due 2015 at 6 1/4%	Aug. 31, 2012 Senior Notes due 2015 at 6 1/4%	Nov. 30, 2011 Senior Notes due 2015 at 6 1/4%	Aug. 31, 2012 Senior Notes due 2017 at 9.10%	Nov. 30, 2011 Senior Notes due 2017 at 9.10%	Aug. 31, 2012 Senior Notes due 2020 at 8.00%	Nov. 30, 2011 Senior Notes due 2020 at 8.00%	Jul. 31, 2012 Senior Notes due 2022 at 7.50%	Aug. 31, 2012 Senior Notes due 2022 at 7.50%	Nov. 30, 2011 Senior Notes due 2022 at 7.50%
Debt Instrument [Line Items]
Letter of credit facility outstanding	$ 45,200,000		$ 45,200,000		$ 63,800,000
Senior notes															265,000,000		350,000,000			350,000,000
Senior notes, rate							5.75%	5.75%		5.875%	5.875%		6.25%	6.25%	9.10%	9.10%	8.00%	8.00%		7.50%	7.50%
Percentage of price equal to the redemption value of senior notes																	100.00%			100.00%
Percentage of principal amount for purchase of notes if change in control																	101.00%			101.00%
Proceeds from issuance of senior notes			694,831,000	0															252,200,000
Amount of debt repurchased						117,700,000			67,800,000			59,400,000
Loss incurred related to early redemption of debt	8,300,000		10,300,000
Total consideration paid to purchase the notes			340,500,000				56,300,000			130,000,000			153,700,000
Loss on early redemption of debt		2,000,000
Principal payments on senior notes, mortgages and land contracts due to land sellers and other loans due 2012	1,700,000		1,700,000
Principal payments on senior notes, mortgages and land contracts due to land sellers and other loans due 2013	10,100,000		10,100,000
Principal payments on senior notes, mortgages and land contracts due to land sellers and other loans due 2014	75,900,000		75,900,000
Principal payments on senior notes, mortgages and land contracts due to land sellers and other loans due 2015	384,600,000		384,600,000
Principal payments on senior notes, mortgages and land contracts due to land sellers and other loans due 2016	0		0
Principal payments on senior notes, mortgages and land contracts due to land sellers and other loans due thereafter	$ 1,260,000,000		$ 1,260,000,000